1. Field of the Disclosure
This disclosure relates in general to the preparation of internal fluorobutenes and internal fluoropentenes using halobutanes and halopentanes as starting materials respectively in vapor phase processes catalyzed by chromium oxyfluoride.
2. Description of Related Art
CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons) have been employed in a wide range of applications, including their use as aerosol propellants, refrigerants, cleaning agents, expansion agents for thermoplastic and thermoset foams, heat transfer media, gaseous dielectrics, fire extinguishing and suppression agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents. Due to the belief that CFCs and HCFCs are contributing to depletion of stratospheric ozone, there has been extensive work in the past two decades on replacement of these materials with non-ozone depleting substances. Hydrofluorocarbons (HFCs), which do not contain chlorine, have replaced CFCs and HCFCs in a number of applications. Although HFCs do not contribute to the destruction of stratospheric ozone, they are of concern due to their potential contribution to the “greenhouse effect” (global warming). Thus, there is a need for compositions in the applications noted above that do not contribute to the destruction of stratospheric ozone and also have low global warming potentials (GWPs). Certain hydrofluoroolefins, such as internal fluorobutenes and internal fluoropentenes in this disclosure, are believed to meet both goals.